This invention relates to blends of carbonate polymers with rubber-modified monovinylidene aromatic polymers.
Carbonate polymers derived from reactions of dihydroxyorganic compounds, particularly the dihydric phenols, and carbonic acid derivatives such as phosgene have found extensive commercial application because of their excellent physical properties. These thermoplastic polymers appear suitable for the manufacture of molded parts wherein impact strength, rigidity, toughness, heat resistance, excellent electrical properties, glass-like transparency and good clarity are required.
Unfortunately, however, these polymers are expensive in price and require a high amount of energy expenditure in extrusion and molding processes. In order to reduce the cost of processing carbonate polymers, said polymers may contain additives that reduce costs and lower the temperatures required for molding processes. The blends resulting from the processing of carbonate polymer and additive generally exhibit improved melt flow properties at the sacrifice of other desirable features such as heat resistance, impact strength, and the like. In addition, blends of carbonate polymer and additive often exhibit an undesirable, glossy finish.
In view of the deficiencies of the conventional carbonate polymers and blends thereof, it would be highly desirable to provide an economical carbonate polymer composition which exhibits improved processability while retaining, to some degree, the desirable properties characteristic of carbonate polymers such as impact strength and heat resistance, and exhibiting a very low gloss finish.